Mechanical excavators



June 15, 1965 N. BRQCKLEBANK ETAL 3,189,293

MECHANICAL EXCAVATORS 4 Sheets-Sheet l Filed Aug. 26, 1963 June 15, 1965 N, BROCKLEBANK ETAL 3,189,203

MECHANICAL EXCAVATORS Filed Aug. 26, 1965 4 Sheets-Sheet 2 June l5, 1965 Filed Aug. 2e, 196s N. BROCKLEBANK ETAL 3,189,203

MECHANICAL ExcAyAToRs 4 `Sheets-Sheet 3 e wwwa-5.5m#

By E i Mtmfneys June 15, 1965 N. BROCKLEBANK ETAL 3,189,203

MECHANICAL EXCAVATORS Filed Aug. 26, 1963 4 SheetsSheet 4 3,189,203 MECHANICAL EXCAVATRS Norman ilro'chlehank, Iieverley, and Roy Warrlill and Gordon Scott, Hull, Eng-tand, assigners to Priestrnan Brothers Limited, Huli, England, a British company Filed Aug. 26, 1963, Ser. No. 3%,586 Claims priority, application Greatrritain, Ang. 23, i962, 33,0i96/62 3 Claims. (Cl. 2314-433) `It is very desirable for mechanical excavatorsto be adaptable so that they can be put to as many uses as is reasonably practicable. Commonly, shovels whichhave a boom and an arm pivoted together with Va digging bucket mounted on the outer end of the arm are arranged so that they can be operated both as drag shovels and also face shovels. For this purpose the bucket or shovel shouid be reversible and may be constructed as described in the copending US. patent application of Norman Brocklebanlt and Gordon Scott, SenNo. 294,648, tiled J'uly l2, 1963.

When the excavator is operating as a tace shovel it is desirable for the boom to `be shorter than it is necessary for it to be when the excavator is operating as a drag shovel. It is desirable to have the boom shorter when the excavator is operating as a face shovel because the shorter the boom the heavier the load which can be handledby the excavator and also the excavator can United States Patent O the inner part or in their extended position in which the outer part extends upwards and outwards from the inner part.

With this arrangement the length of the boom can be considerably reduced when the excavator is travelling or is parked. However, the invention is particularly applicable to excavators in which the bucket is reversible on the end of the arm so that the excavator can be used alternatively as a drag shovel or a face shovel. When the excavator is used as a face shovel the boom -is retracted, that is to say the outer or upper part is slid telescopically within the lower or inner part of the boom and the resulting boom is extremely rigid and very heavy loads can be handled. The excavator may indeed be one of the kind described in said US. application Serial No. 294,648 in which the bucket has two connections one near the top and one near the bottom by either of URE V;

which the bucket can alternatively be pivotally mounted on the arm and there is a link which is pivoted to the bucket and by which the bucket can be rocked about its pivot on the arm during digging and for discharging its contents, the link incorporating a swivel which allows the bucket, when attached to the arm by one connection, to oe disconnected, turned around on the swivel so that the bucket faces in an opposite direction relatively to the arm, and `then attached again to the arm by the other connection.

It is desirable for the lower or inner boom part to be the stiffer and for Ithis purpose the lower part may consist of two closed box sections arranged side by side with a bottom plate extending between them. The outer boom part is then arranged to slide on the bottom plate between the two box sections. i

Preferably the telescopic arrangement of the two boom par-ts is combined with the arrangement described in US. patent application Ser. No. 304,585, filed August 26, 1963, by Norman Brocklebank and Gordon Scott. Thus the means for fixing the two boom parts together in their extended position allows the` outer part to slew from side to side relatively to the inner part and to be iixed to the inner part in any one of three diiterent positions in the rst of which the two parts of the boom are aligned with each other so that the axis of the boom is straight as seen from above, and in the other two of which the outer part of the boom is set at angle laterally as seen from above to the inner part of the boom, the outer part being oi-set'in opposite directions in these two positions.

This oli-setting of the outer part of the boom to either one side or the other is extrernely useful when the excavator is being used as a drag shovel for excavating trenches.

It enables the trench to be excavated alongside a wall or other obstruction by slewing the superestructura of the machine in one sense on the chassis of the machine and slewing the outer upper part of the boom in the other sense relatively to the inner lower part of the boom and locking the two parts together in this relative position. When this is done the vertical plane containing the outer part of the boom is laterally off-set from the central longitudinal lineof the chassis so that a trench can be dug which is in line with the side edge of or even outside the wheel base of the chassis.

Preferably the iixing means for fixing the two parts of the boom together in their extended and retracted positions consists of sockets in the two` boomparts and a pin which is arranged to pass through aligned sockets in the boom in each position. In order to strengthen the boom, the `two parts may additionally be secured together by bolts in the two positions. i

One example of an excavator constructed in accordance with the present invention is illustrated in the accompanying drawings, in which:

FGURE I is a side elevation of the excavator set up for use as a drag shovel with the boom extended;

FIGURE II is a side elevation of the excavator set up for use as a face shovel with the boom retracted;

FIGURE III is a side elevation of the boom per se in its extended position and with the outer part aligned with the inner part;

FIGURE IV is a plan of lthe exten-ded boom as shown in FIGURE III;

FIGURE V is a side elevation of the boom per se in its retracted position;

FIGURE Vl is a plan of the boom as shown in FIG- FIGURE VII is a section on the line FIGURE IV;

FIGURE VIII is a section on the line VIII toVlII in FIGURE IV; and,

FIGURE IX -is a section on the line IX to IX in FIG- URE IV.

VII to VII in The excavator, which is the same machine as that illustrated and described in the copending application Ser. No. 304,585, previously referred to, consists of a superstructure 1 which is carried through a turntable 2 on a ytrack laying chassis 3. An inner part 4 of a steel box lshaped boom is pivoted at its lower end ,to a bracket S on the superstructure 1. The boom can be raised and lowered by means of a pair of hydraulic rams 6 which extend between lugs '7 on the superstructure and lugs S at the outer end of the inner boom part 4.

The upper or outer part of the boom 9, which can telescope withinthe inner boom part 4, is arranged when extended to slew relatively to the inner part 4 and to be iixed in :any one of three different positions relatively tothe inner part 4. A digging arm 1li having a plateli at each side is pivoted by means of the brackets at I2 to the upper end of the boom part 9 to enable the digging arm i@ to swing backwards and forwards on the other end of the boom. This swinging movement is controlled by a hydraulic ram I3 one end of which is anchored ybetween lugs iid on the inner end of the outer boom part 9 and the other end of which is anchored to a bracket 15 carried between the plates Il. A digging bucket 16 is pivotallyrnounted on the outer end of the arm and can be rocked backwards and forwards on the end of the arm by a hydraulic ram 17. One end of the ram 17 is anchored to the plates Il and the other end is connected to ianges ll on the back of the bucket through a swivel link I9. The bucket has two alternative connections 20 and 2l by either of which it can be connected to the end of the arm lil. The arrangement is such that the bucket can be disconnected from the arm I0, swung around through 180 on the swivel 19 `and reconnected by the other connection 29 or Z1 to the arm lit. In this way the excavator can be converted from a drag shovel or back actor to a face shovel and vice versa easily. This arrangement is fully described and claimed in the copending application Ser. No. 294,648, previously referred to.

The construction of the two boom parts d and 9 which enables the outer part 9 to slew relatively to the inner part and to telescope into the inner part is shown most clearly in FIGURES II to IX. The inner boom part 4l consists of two box sections ZZ arranged side by side and connected by a bottom plate 23 which is welded to them. The-two box sections increase in depth from a minimum at the inner end to a maximum a short distance away from the outer-end. The inner boom part is therefore substantially U shaped in section and the outer boom part 9 is arranged to slide within the trough of the U between the box sections 22, on the base plate 23, and beneath inturned lips 23a on the inner walls of the box sections. These inner walls of the box sections 22 extend above the sections as they taper in a direction towards the inner end of the boom to provide a channel of constant height to receive the inner end of the outer boom part 9 as it telescopes within the innerpart. At their extreme inner ends, the box sections 22 terminate in tubular sockets 24 for receiving a pivot pin which connects the inner end of the boom to the bracket 5. At its extreme outer end, the boom part fi is strengthened with upper and lower plates 2S and 26 respectively which defines between them an enlarged housing 27 which enables the extreme inner end of the outer part 9 to move from side to side when the outer boom part 9 is slewed relatively to the inner part 4. The bottom plate 26 extends across the full width of the boom but the upper plate has its centre and rear portion cut away to provide access to the housing 27. The lugs 8 for the rams 6 are welded to the top plate 25.

The outer boom part 9 is also of box construction and consists of four plates welded together at each corner of the section. There is a portion 28 of constant height iat the :inner end of the boom part 9 but beyond this the rest of the boom part tapers towards its outer end. At its extreme outer end the part 9 is formed with a tubular socket Z9 tor receiving a pivot pin which connects the plate brackets Il to the end of the boom.

Adjacent its inner end the outer boom part 9 is formed with a tubular socket 3i) and adjacent its outer end is formed with another tubular socket 31 of similar shape and size to the iirst one. The socket 3l is supported by la web 32 where it projects above the tapering box section of the boom part 9 so that it has the same height as the socket 3th. When the boom is in its fully extended position as shown in FIGURES I, III and IX, a pivot pin 33 extends down through the socket 30 and through aligned tubular sockets 34 and 35 in the upper plate 5 and in the lower plates 23 and 26 respectively to connect the two boom parts together. The outer boom part 9 is free to slew about the pivot pin 33 but it can be bolted in any one of three positions in which it extends straight forwards in alignment with the inner boom part d as shown in FIGURES III and IV or at an angle or" 25 to one side or the other. The outer boom part 9 can be rigidly xed in the straight ahead position shown in FIGURES III and IV by means of three bolts 36, 37 and 3S which pass through sockets in the inner end of the outer boom part 9 and through holes formed in the bottom plates 23 and 26 of the inner boom part i. When the outer boom part 9 is slewed to the left or to the right, the bolts 3'7 and 38 are transferred to holes 39 and 4i) or to holes '4l and 39 respectively in the bottom plates 23 and 26 and the bolt 36 is dispensed with. Instead, the inner end of the boom part 9 is bolted to one or other of the side walls of the housing 27 by apair Vof bolts which pass through a pair of transverse tubular sockets i2 at the inner extreme inner end of the boom part 9 and through a pair of sockets 43 or 44 in one side wall of the housing Z7 or the other. This arrangement is fully described in the copending application Ser. No. 304,585, previously referred to.

The outer boom part 9 can be retracted telescopically within the boom part 4 by unbolting its extreme inner end from the bottom plates or side walls of the housing 27 and removing the pivot pin 33. The outer boom part 9 is then retracted from the position shown in FIGURES I, III and IV to that shown in FIGURES Il, V and VI by withdrawing it through the housing 27 until the socket 3l is aligned with the sockets 3d and 35. It is then secured in position by reinserting the pivot pin 33 through the tubular sockets F14 and 35in the housing 27 and through the socket 31 in the part 9. The inner end of the outer part is also secured by means of the bolts 36, 37 and 3S which now pass through holes d5, 46 and 47 respectively in the plate 23 and in a strengthening plate 48 beneath the plate Z3 at the inner end of the boom part 4. The outer boom part 9 cannot of course slew from side to side relatively to the inner part 4 when it is retracted in this way.

The construction of the boom and the mounting of the bucket 16 on the end of the arm 10 enable the excavator to be very adaptable and to be used for a wide variety of functions. Ir the bucket is mounted as shown in FIGURE I, the machine is ready for use as a back actor or drag shovel. It the two boom parts are extended and locked in the straight ahead'position a trench can be dug in line with the central longitudinal line ofthe chassis. However, if the superstructure l is slewed to one side or the other through 25 and the outer boom part 9 is slewed in the opposite sense relatively to the inner boom part 4 through 25 and locked in this position, the excavator can then dig a trench which is in line with one or other of its tracks.

By turning the bucket 16 around on the swivel i9 and reconnecting it to the arm li) and also retracting the outer boom part 9 within the inner boom part 4, both as shown in FIGURE II, the excavator is ready for use as a face shovel. With the boom retracted in this way, the excavator is also ready for transporting.

We claim:

l. In an excavator of the kind having a body, a boom, means pivotally mounting said boom on said body, a digging arm, means pivotally mounting said digging arm on said boom, a digging bucket mounted on said digging arm; the improvement according to which said boom comprises an inner boom part mounted on said body, an outer boom part carrying said digging arm and adapted to be telescopically slidable into said inner boom part, and means fixing said inner and outer boom parts together either in their contracted position with said outer boom part lying largely within said inner boom part or in their extended position in which said outer boom part extends upwards and outwards from said inner boom part, wherein said inner boom part comprises parallel, laterally spaced, first and second closed box sections and a bottom plate extending between said first and second box sections, said box sections and the bottom plate defining a trough dimensioned to slidably receive said outer boom part.

2. In an excavator of the kind having a body, a boom, means pivotally mounting said boom on said body, a digging arm, means pivotally mounting said digging arm on said boom, a digging bucket mounted on said digging arm; the improvement according to which said boom comprises an inner boom part mounted on said body, an outer boom part carrying said digging arm `and adapted to be telescopically slidable into said inner boom part, and means iixing said inner and outer boom parts together either in their contracted position with said outer boom part lying largely within said inner boom part or in their extended position in which said outer boom part extends upwards and outwards from said inner boom part, Wherein said xing means comprises at least one tubular part in a selected one of said boom parts defining a socket therethrough, a plurality of tubular parts spaced length- Wise along and dening a plurality of sockets in the other of said boom parts, one of the sockets in said other boom part being positioned to be in alignment with a socket of said selected boom part when said boom parts are in their contracted position and another of the sockets in said other boom part being positioned to be in alignment with a socket of said selected boom part when said boom parts are in their extended position, and a pin adapted to pass through said aligned sockets.

3. In an excavator ofthe ldnd having a body, a boom, means pivotally mounting said boom on said body, a digging arm, means pivotally mounting said digging arm on said boom, a digging bucket mounted on said digging arm; the improvement according to Whichsaid boom comprises an inner boom part mounted on said body, an outer boom part carrying said digging arm and adapted to be telescopically slidable into said inner boom part, and means fixing said inner and outer boom parts together either in their contracted position with said outer boom part lying largely within said inner boom part or in their extended position in which said outer boom part extends upwards and outwards from said inner boom part, said excavator comprising iirst connecting means carried by said bucket near the top thereof, second connecting means carried by said bucket near the bottom thereof, third connecting means carried by said bucket intermediate said iirst and second connections, a supporting link carried from said boom and adapted to support said bucket through said third connecting means, swivel means in said link, and means optionally securing said bucket to said digging arm through one of said tirst and second connecting means, said bucket being formed to face toward said body for use as a drag shovel when connected to said digging arm through said lirst connecting means with said boom in its extended position, and to face away from said body for use as a face shovel when connected to said digging arm through said second connecting means with said boom in its contracted position.

References Cited by the Examiner UNITED STATES PATENTS 2,767,869 10/56 Miller 214--141 2,827,186 3/58 Waite 214-141 HUGO O. SCHULZ. Primary Examiner. 

1. IN AN EXCAVATOR OF THE KIND HAVING A BODY, A BOOM, MEANS PIVOTALLY MOUNTING SAID BOOM ON SAID BODY, A DIGGING ARM, MEANS PIVOTALLY MOUNTING SAID DIGGING ARM ON SAID BOOM, A DIGGING BUCKET MOUNTED ON SAID DIGGING ARM; THE IMPROVEMENT ACCORDING TO WHICH SAID BOOM COMPRISES AN INNER BOOM PART MOUNTED ON SAID BODY, AN OUTER BOOM PART CARRYING SAID DIGGING ARM AND ADAPTED TO BE TELESCOPICALLY SLIDABLE INTO SAID INNER BOOM PART, AND MEANS FIXING SAID INNER AND OUTER BOOM PARTS TOGETHER EITHER IN THEIR CONTRACTED POSITION WITH SAID OUTER BOOM PART LYING LARGELY WITHIN SAID INNER BOOM PART OR IN THEIR EXTENDED POSITION IN WHICH SAID OUTER BOOM PART EXTENDS UPWARDS AND OUTWARDS FROM SAID INNER BOOM PART, WHEREIN SAID INNER BOOM PART COMPRISES PARALLEL, LATERALLY SPACED, FIRST AND SECOND CLOSED BOX SECTIONS AND A BOTTOM PLATE EXTENDING BETWEEN SAID FIRST AND SECOND BOX SECTIONS, SAID BOX SECTIONS AND THE BOTTOM PLATE DEFINING A TROUGH DIMENSIONED TO SLIDABLY RECEIVE SAID OUTER BOOM PART. 